Hi All,
Started work in on the roll bars again. I worked out a design for the 3rd leg and have nearly got the passengers side finished.
There's no provision for a 3rd leg mount on the old square tube chassis so you have to make your own up. I had made one for the drivers side wit the old roll bar but was never completely happy with it. I'm much happier with the new setup.
I machined up a threaded boss and welded it into a short section of tube cut at the right angle to fit snug up against the underside of the boot floor. This is then welded onto the rear cross member behind the diff. There's a hole drilled into the cross member for the bolt to run down into.
One of the things I didn't like about my old mount was that it crushed the fiberglas between the mount and the flange on the roll bar. With this setup I machined an aluminium bush that goes between the roll bar flange and the mount. This is stepped to go through the fiberglass and sandwich in place but not crush it. The boot floor has a foam core mat between 2 laminated layers and is about 8-9mm thick.
My TIG has been giving me grief lately I think the torch is stuffed because it just won't throw a consistent arc. It wanders and is hard to control so the welds are a bit crappy. It doesn't matter though since they will be linished back and polished out.
Here's the slip joint at the top. There's a stainless steel slug welded into the down tube and this slides into a socket on the roll bar. It's hald in place with 2x 10mm stainless countersunk cap screws. Again crappy welds will be polished out.
Cheers